Hello Mr.Moo
You can fix this by adding some css for the theme you are using. In your case this should do:
.jqx-fill-state-disabled-black {
background: #a4a4a4;
background: -moz-linear-gradient(top, #a4a4a4 0%, #757575 4%, #4f4f4f 37%, #464646 48%, #000000 52%, #000000 56%, #0c0c0c 67%, #1e1e1e 78%, #414141 96%, #666666 100%);
background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,#a4a4a4), color-stop(4%,#757575), color-stop(37%,#4f4f4f), color-stop(48%,#464646), color-stop(52%,#000000), color-stop(56%,#000000), color-stop(67%,#0c0c0c), color-stop(78%,#1e1e1e), color-stop(96%,#414141), color-stop(100%,#666666));
background: -webkit-linear-gradient(top, #a4a4a4 0%,#757575 4%,#4f4f4f 37%,#464646 48%,#000000 52%,#000000 56%,#0c0c0c 67%,#1e1e1e 78%,#414141 96%,#666666 100%);
}
Add it to the appropriate theme file, or at least somewhere after loading the theme.
Best Regards,
Vladimir
jQWidgets Team
http://www.jqwidgets.com